Air-blast pressure attachment for presses



. W. COTTTRELL. AIR BLAST PRESSURE ATTACHMENT FOR PRESSES.

- APPLICATION FILED SEPT. 18, 1919.

1 ,337,000, Patented Apr. 13, 1920.

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WILLIAM German, or mvnnsmn, ILL'moIs',"- Jnsfsieno1z roflann'mmm anaemic MANUFACTURING COMPANY, or CHIGAGOQIIELINQIS, A CORPORATION or ILLI- NOIS.

AIR-BLAST PRESSURE ATTACHMENT FOR PRESSES.

Specification of Lett ers Patent. Patented Apr. 13, 1920.

Application filed September 18. 1919. Serial No. 324,320.

To all whom it may concern:

Be it known that I, VILLIAM COTTRELL, a citizen of the United States, residing at Riverside, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Air-Blast Pressure Attachments for Presses, of which the following is afull, clear, concise, and exact description, reference being had to' the accompanying drawing, forming a part of this specification.

My invention relates to improvements in mechanism for removing the stampings and the like from presses, etc.,.by means of a blast of air. It has been found that by removing the stampings from the press by air pressure the speed of the operator 1s greatly increased, and, at the same time, the blast of air keeps the dies clean, thereby insuring sharper work and insuring longer life on the part ofthe dies. This air blast is usually supplied from a storage tank or from some other operating mechanism operatedindependently of the press.

It is one of the objects of my invention to provide a means whereby the air blast may be supplied by mechanism operated directly from the press. In the operation of the machine, a quantity of air is compressed into a relatively small compression chamber at each stroke of the press and the air thus compressed into this chamber is suddenly released while under a high state of compression. at the proper time of each stroke of the press automatically, through the operation of the machine. For the purpose of disclosing my invention I have illustrated in the accompanying drawings one embodiment thereof:

In the drawings- Figure 1 is a side elevation, partly in section, of a press showing my invention in connection therewith;

Fig. 2 is a cross-sectional detail of a portion of Fig. 1 showing the valve 3 and Fig. 3 is a section on the line 3-3 of Fig. 1.

In the drawings 1 have shown the usual form of stamping press, the character of which is well known and need not be described fully. On one side of the press I provide a compression air pump which comprises a cylinder 6 and a piston 7 operating in the cylinder 6, the piston 7 being provided with the usual leather packing 8 and having a one-way valve 9, the valve being constructed to close on the down stroke of the piston and open on the up stroke. Secured to this piston is a piston-rod 10 which projects upwardly through an opening in the cylinder head, and is pivotally connected to an operating link 11. The upper end of this operating link is connected to a crank member 12 secured on an end of the crank shaft of the ram of the press. This crank member is slotted at 13 to receive a bolt 14, to which the link 11 is secured.

The head of the bolt 14 fits within the slot and a suitable nut 15 on the outer portion of the bolt securely clamps the bolt in any position to which it may be moved in the slot. The link 11 is secured in position by a suitable thumb nut 15. By this arrangement, the link operating the piston 10 may be varied at will tosuit varying conditions, and if desired to operate the press without the air press, the end of the link may be shifted until it is directly over the center of the crank shaft thence, of course, the piston will not receive any movement whatever. The lower end of the cylinder 6 is provided with a cylinder head 19 and underneath the cylinder 6 is provided a cylindri' cal storage tank 20, having ears 21 by which it may be bolted by suitable bolts to the frame of the press. In the cylinder head 19 of the pump cylinder is a spring pressed valve '22 constructed to open on the downward stroke of the piston 7 and to be closed on its upward stroke.

Thus, it will be seen. the pump, is constructed to compress a quantity of air into the relatively small storage tank 20 on each stroke of the press. The storage tank 20 may, if desired, be provided at its lower end with a plurality of hose connections 23. In the .form illustrated there are three of these connections, two of them, however, being shown as closed by suitable pipe caps. To one of these connections 23 is attached a hose 24 leading to an apparatus for automatically releasing the air compressed in the tank 20 on each stroke of the press. This apparatus comprises a valve 25 facing the pipe or hose 24 and having a stem 26 proclined across the path of a tripping member 28 carried by the ram of the press. A. hose 29 leads from the valve to a blast nozzle 30. The tripping member is aranged -to strike the trigger 27 thus forcing the stem 26 inwardly and opening the valve on every upward stroke of the ram, and it is adjustable to vary the time of the blast with respect to the position of the ram and also to vary the intensity and duration of the blast.

To the other hose connections, if desired, may be attached lines of hose other presses not provided with a pump. The connections not being used may be suitably closed. In the side of the tank is a safety valve 31 for releasing the air if the pressure becomes too great.

It will be seen that the construction described provides a' relatively small compression-chamber in which air is compressed at each stroke of the press and from which it is suddenly released also at each stroke of the press at just the proper time and at a time when the air is under a relatively high degree of compression, to deliver a quick blast of air at the desired point.

Not only does this device provide a selfcontained mechanism operated directly from the press for supplying an air-blast to the dies, but the device acts as a partial brake with respect to the rotation of the crankshaft when the clutch is released. Heretofore, in order that the ram of the press will stop immediately upon the throwing out of the clutch, it has been necessary to operate This brake-is con-. tinuously applied to the crank-shaft of the the press under a brake.

press so that it will stop the press as soon as power is released from the crank-shaft.

For the construction of my blast mechanism above described, I utilize what has heretofore been a waste of power to deliver a blast of air to a die for the purpose of removing the stampings and for the purpose of eeping the dies clean. The valve 25 is instrumental in producing the braking effect as it does not permit the escape of air on the downstroke of the ram, thus causing the air to be compressed, so that a substantial resistance is offered to the rotation of the crankshaft, which (in cooperation with the brake if one is provided) will leading to r sco e of the appended claims.

his case is a continuation in part of my previous application Serial N 0. 838,228, filed May 13, 1914, which it is proposed to abandon in favor ofthis application.

\ Having thus described my invention, what I clalm asnew. and desire to secure by Letters Patent is:

1. The combination with a press, of a relatively small air compression chamber,

means whereby each stroke of the press causes air to be compressed into said compression chamber, and whereby each stroke of the press causes-air to be suddenly released from said small compression chamber at a time when the air is under relatively high compression.

2. The combination-with a press, of a relatively small air compression chamber, means whereby each stroke of the press causes air to be compressed into the air compression chamber, and whereby each stroke of the press causes air to be suddenly released from said small compression chamber under relatively high compression, and means whereby the resistance to compression of the air in said chamber causes a retarding effect on the operation of the press.

3. The combination with a press, of a relatively small compression chamber, means whereby each stroke of the press causes air to be compressed into said compression chamber, and whereby each stroke of the press causes air to be suddenly released from said compression chamber at a time when the air is under relatively high compression, and whereby the resistance to compression of the air in said chamber causes a retarding effect on the operation of the press, said means comprising an automatically operated valve.

In witness whereof I have hereunto subscribed my name.

WILLIAM COTTRELL. 

